Inconsistent lightmap?
Hello, wise polycount people!
I seem to have a problem with my modular assets and their lightmaps. While making a wall tileset, I happened to notice that two assets that were made using THE SAME TECHNIQUE, UV'd in the same way and exported, you guessed it, in the same way, have drastically different lightmaps.
As you've probably noticed, the lightmap of the corner-wall model is considerably more pronounced. What could be causing this and how can I fix it?
I already tried:
-Closing the meshes
-Realigning the UVs
-Remaking the second mesh
I even tried exporting two instances of the straight wall into a file to imitate the positions of the corner wall. They had the same lightmap problem as the corner wall!
This leads me to believe this is not a UV problem (I ruled that out through the above experiment) and is indeed something to do with the mesh itself.
Please help! I have not the faintest clue what to do with this.
I seem to have a problem with my modular assets and their lightmaps. While making a wall tileset, I happened to notice that two assets that were made using THE SAME TECHNIQUE, UV'd in the same way and exported, you guessed it, in the same way, have drastically different lightmaps.
As you've probably noticed, the lightmap of the corner-wall model is considerably more pronounced. What could be causing this and how can I fix it?
I already tried:
-Closing the meshes
-Realigning the UVs
-Remaking the second mesh
I even tried exporting two instances of the straight wall into a file to imitate the positions of the corner wall. They had the same lightmap problem as the corner wall!
This leads me to believe this is not a UV problem (I ruled that out through the above experiment) and is indeed something to do with the mesh itself.
Please help! I have not the faintest clue what to do with this.
Replies
You might be better off using vertex lighting (resolution 0)
I'm gonna have to check out the UVs of the original model but I don't think that's it, JamesWild. Remember that even if I import the straight wall twice the second one has this problem too, for some reason.
EDIT:
OK, I am *dead certain* the UVs of both objects are pixel-aligned and have the right lightmap resolution. Still no dice. What now?
EDIT2:
In hopes that it IS in fact my UV mapping that is the problem, I post my UVs, along with an explanation:
The 'corner wall' UV set is just the original straight wall UVs copied over, scaled down twice and pixel-aligned to a 256x256 texture (whereas the original straight wall UVs are pixel-aligned to a 128x128 texture because they take up the whole space instead of half of it).
So, in the end, the UVs are pretty much the same. They're exactly the same from a technical standpoint, unless I'm missing something. Help?
What is this sorcery!?
I even tried using the REALLY exact same UVs as in the straight wall, which meant using channel 0 in the corner wall as the lightmap UVs. Same thing.
Haaaaaaaaaalp! XD
This is driving me crazy o.O
EDIT:
I made a completely new scene with only the wall models and a single dominant light. The problem is still there.
EDIT:
Upon closer inspection, I've found that even the straight walls tend to not line up properly, albeit in a slightly different manner:
Is this the same problem?
Sorry for useless answer. ^^
Try disabling AO in the lighting build?
...Please...?
...I beg of you...?!
Don't put so many seams in your lightmap UVs. It doesn't look like it's necessary for this model.
The picture above is not my model. I'm talking about my wall models, not the rock thing - that's someone else's. My UVs have almost no seams.
But Mip-mapping is only an issue when the UVs are not edge-to-edge of the texture! Besides, my corner wall UV already had A LOT of padding so it can't be it.
Maybe it's an issue with how it's all modelled? I thought that maybe it's because the meshes are 'open' but that turned out to not be the issue.
I really don't know what to do anymore ;( And I really need to complete this project...!
Then finish the model texture first and then worry about the seams. At least get a baked normalmap and ambient occlusion map on their first.
EDIT : I realise I have a good example of what I'm talking about:
here's a scene without any normalmaps on some pieces
RH_working_ss070211 by sprunghunt, on Flickr
If you look at it you can see on the left there's a seam in the tiling pieces under the window which I hadn't finished.
and here's the same scene with normalmaps and AO on those pieces.
RH_working_ss200211 by sprunghunt, on Flickr
No seam on the pieces under the window.
And I still get this problem
And the lightmap difference is waaay to noticeable to disappear under a diffuse texture...
What nao?
try this tutorial. it hasnt fixed our problem, but maybe you can better interpret it and understand the principal behind this practice.
http://www.worldofleveldesign.com/categories/udk/udk-lightmaps-03-how-to-fix-light-shadow-lightmap-bleeds-and-seams.php
what does your normalmap look like?
and if you really can't get rid of it then hide the seams.
That's what the normal map looks like.
Im not sure how you baked the normal map, it looks like it was your current mesh, baked to a plane, and then applied back on to your current mesh. The problems are most visible along the top section that slopes down. It could also be because its not broken up into enough smoothing group, depending on angle of the polygons.
What I think you after are smooth corners, in which case you what a high poly with chamfered corners, projected and baked on to your current mesh. Check out the polycount wiki, there is pretty much all the information you could want on normal maps: http://wiki.polycount.com/NormalMap/
It is also my understanding that uv's for your light map should be broken into separate smoothing groups, rather than one whole uv shell.
My current suggestion would be break up your mesh into separate smoothing groups (and also your light map uv's) and then try baking the light maps. If you get successful results, come back to figuring out your normal map and see if you can get better results.
Which means it's not a problem with the mesh structure but rather something else. It's also independent of the normal maps as the problem persists even with the normal map turned off.
Thanks, but that's not the problem.
I'm going to try, however, playing around with separate lightmap uvs, as you suggested! Will post what came of that soon.
EDIT:
Through experimentation I figured out that the most probable reason for the graphical glitch is that UDK kind of freaks out with small geometry like the indent on the wall when calculating lightmaps. Either that, or my workflow must have made my UV maps somewhat off, although I doubt that's that happened.
Either way, removing the indent from geometry and leaving it baked on the normal map fixed my problem. Thanks for all the help guys